1. Field of the Invention
The invention relates to a method for making tris (8-hydroxyquinoline) aluminum (Alq3), particularly, to a method for making Alq3 nano-crystal.
2. Discussion of Related Art
Tris (8-hydroxyquinoline) aluminum (Alq3) has high thermal stability, good chemical stability, excellent electronic transmission performance and luminescent properties. Due to these and other properties, Alq3 is widely used in a variety of fields, such as organic light-emitting diodes, large-screen displays, field emission films, and fluorescent markings. With the development of nano-science and technology, the synthesis of Alq3 nano-crystals with uniform structure attracted a great deal of attention.
Nowadays, the main synthetical method for preparing the Alq3 nano-crystals is vapor method. A steam-condensed method is used to manufacture Alq3 nano-spheres and Alq3 nano-wires, but crystal nano-spheres are not acquired. An adsorbent-assisted physical-vapor-deposition (PVD) method is used to prepare Alq3 nano-wires. However, the above methods for synthesizing Alq3 nano-crystals are complicated, require special equipment, need higher reaction temperature and consume a tremendous amount of protective gas (some of which is expensive rare gas), and as a result, greatly increase the cost of synthesizing the Alq3 nano-crystals. Therefore, these methods are not ideal for large-scale production. Moreover, the Alq3 nano-crystals manufactured via the above methods are difficult to form a film with compact and homogeneous morphology, and thereby restricting its actual application.
What is needed, therefore, is a simple, low cost, and useful large-scale production method for making Alq3 nano-crystals and for forming a film of Alq3 nano-crystals.